20th century conflict (1900-1950)

add latter

ww1

1912 - 1913
1913
28 june 1914
7/28/1914 - 11/11/1918
5 August 1914 - 16 August 1914
12 april 1915 - 14 april 1915
25 April 1915 - 9 January 1916
25 september 1915
21 feb 1916 - 18 December 1916
1 july 1916 - 18 november 1916
19 july 1916 - 20 july 1916
6 april 1917
3 march 1918
11 november 1918